CVE-2017-2982 in Flash Player
Summary
by MITRE
Adobe Flash Player versions 24.0.0.194 and earlier have an exploitable use after free vulnerability in a routine related to player shutdown. Successful exploitation could lead to arbitrary code execution.
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Analysis
by VulDB Data Team • 08/14/2020
Adobe Flash Player contained a critical use after free vulnerability in its shutdown routine that affected versions 24.0.0.194 and earlier. This vulnerability arises from improper memory management during the player termination process where freed memory blocks are still referenced or accessed by subsequent operations. The flaw occurs when the application attempts to execute cleanup code that references memory locations that have already been deallocated, creating opportunities for attackers to manipulate the memory state and execute malicious code. The vulnerability is classified as a use after free condition under CWE-416, which represents a well-known class of memory safety issues that frequently lead to remote code execution exploits. Attackers could leverage this weakness by crafting specially designed flash content that triggers the vulnerable shutdown routine, causing the player to access freed memory and potentially execute arbitrary code with the privileges of the Flash Player process. This type of vulnerability falls under the ATT&CK technique T1059.007 for command and scripting interpreter, as it enables attackers to execute malicious code through the Flash Player runtime environment. The impact of successful exploitation extends beyond simple code execution, as it could allow attackers to bypass security controls, install persistent backdoors, or escalate privileges within the compromised system. The vulnerability demonstrates the inherent risks associated with complex multimedia frameworks that handle untrusted content, particularly when memory management routines are not properly validated during application termination phases. Organizations running affected Flash Player versions faced significant risk exposure due to the widespread use of Flash content across web applications and the difficulty in completely isolating Flash execution environments from other system components.
The technical exploitation of this vulnerability requires attackers to understand the memory layout and timing conditions during Flash Player shutdown sequences. The use after free condition typically manifests when the application's cleanup code attempts to access objects or memory regions that were previously freed during the normal execution flow. During the player shutdown process, specific data structures related to plugin management or resource cleanup may be freed but still referenced by callback functions or asynchronous operations. This creates a window of opportunity where attackers can overwrite the freed memory with malicious content and then trigger the vulnerable code path to execute their payload. The vulnerability is particularly dangerous because Flash Player typically runs with elevated privileges and has extensive access to system resources, making successful exploitation potentially catastrophic for system security. The flaw represents a classic example of memory safety issues that can be exploited through carefully crafted input, as attackers can manipulate the timing and content of flash objects to ensure proper exploitation conditions are met. Security researchers have noted that such vulnerabilities often require multiple conditions to be met for successful exploitation, including proper memory layout and timing constraints that make them both challenging to detect and difficult to prevent without comprehensive memory safety measures.
Organizations affected by this vulnerability needed to implement immediate mitigations to protect their systems from potential exploitation attempts. The primary recommendation was to update to Adobe Flash Player version 25.0.0.127 or later, which contained patches addressing the memory management issues in the shutdown routine. System administrators should also consider implementing additional security controls such as sandboxing mechanisms, network segmentation, and content filtering to reduce the attack surface for Flash-based exploits. Browser vendors and security teams often recommended disabling Flash Player entirely in environments where it was not strictly required, as the complexity and security risks associated with multimedia frameworks frequently outweigh their benefits. The vulnerability highlighted the importance of proper memory management practices in software development, particularly for applications that handle untrusted input from external sources. Security monitoring systems should be configured to detect unusual memory access patterns and potential exploitation attempts related to Flash Player processes. Additionally, the incident reinforced the need for comprehensive vulnerability management programs that include regular patching, security assessments, and incident response procedures to address similar issues in other software components. Organizations with legacy systems relying on Flash content needed to develop migration strategies to reduce dependency on potentially vulnerable technologies while maintaining business continuity. The vulnerability also demonstrated the necessity of continuous security monitoring and threat intelligence to identify and respond to emerging threats targeting widely deployed software components.